#include <iomanip>

#include "asyncsocket.h"
#include "logging.h"
#include "socketfactory.h"
#include "socketpool.h"
#include "socketstream.h"
#include "thread.h"

namespace base {

	///////////////////////////////////////////////////////////////////////////////
	// StreamCache - Caches a set of open streams, defers creation to a separate
	//  StreamPool.
	///////////////////////////////////////////////////////////////////////////////

	StreamCache::StreamCache(StreamPool* pool) : pool_(pool) {
	}

	StreamCache::~StreamCache() {
		for (ConnectedList::iterator it = active_.begin(); it != active_.end();
			++it) {
				delete it->second;
		}
		for (ConnectedList::iterator it = cached_.begin(); it != cached_.end();
			++it) {
				delete it->second;
		}
	}

	StreamInterface* StreamCache::RequestConnectedStream(
		const SocketAddress& remote, int* err) {
			LOG_F(LS_VERBOSE) << "(" << remote << ")";
			for (ConnectedList::iterator it = cached_.begin(); it != cached_.end();
				++it) {
					if (remote == it->first) {
						it->second->SignalEvent.disconnect(this);
						// Move from cached_ to active_
						active_.push_front(*it);
						cached_.erase(it);
						if (err)
							*err = 0;
						LOG_F(LS_VERBOSE) << "Providing cached stream";
						return active_.front().second;
					}
			}
			if (StreamInterface* stream = pool_->RequestConnectedStream(remote, err)) {
				// We track active streams so that we can remember their address
				active_.push_front(ConnectedStream(remote, stream));
				LOG_F(LS_VERBOSE) << "Providing new stream";
				return active_.front().second;
			}
			return NULL;
	}

	void StreamCache::ReturnConnectedStream(StreamInterface* stream) {
		for (ConnectedList::iterator it = active_.begin(); it != active_.end();
			++it) {
				if (stream == it->second) {
					LOG_F(LS_VERBOSE) << "(" << it->first << ")";
					if (stream->GetState() == SS_CLOSED) {
						// Return closed streams
						LOG_F(LS_VERBOSE) << "Returning closed stream";
						pool_->ReturnConnectedStream(it->second);
					} else {
						// Monitor open streams
						stream->SignalEvent.connect(this, &StreamCache::OnStreamEvent);
						LOG_F(LS_VERBOSE) << "Caching stream";
						cached_.push_front(*it);
					}
					active_.erase(it);
					return;
				}
		}
		ASSERT(false);
	}

	void StreamCache::OnStreamEvent(StreamInterface* stream, int events, int err) {
		if ((events & SE_CLOSE) == 0) {
			LOG_F(LS_WARNING) << "(" << events << ", " << err
				<< ") received non-close event";
			return;
		}
		for (ConnectedList::iterator it = cached_.begin(); it != cached_.end();
			++it) {
				if (stream == it->second) {
					LOG_F(LS_VERBOSE) << "(" << it->first << ")";
					// We don't cache closed streams, so return it.
					it->second->SignalEvent.disconnect(this);
					LOG_F(LS_VERBOSE) << "Returning closed stream";
					pool_->ReturnConnectedStream(it->second);
					cached_.erase(it);
					return;
				}
		}
		ASSERT(false);
	}

	//////////////////////////////////////////////////////////////////////
	// NewSocketPool
	//////////////////////////////////////////////////////////////////////

	NewSocketPool::NewSocketPool(SocketFactory* factory) : factory_(factory) {
	}

	NewSocketPool::~NewSocketPool() {
	}

	StreamInterface*
		NewSocketPool::RequestConnectedStream(const SocketAddress& remote, int* err) {
			AsyncSocket* socket =
				factory_->CreateAsyncSocket(remote.family(), SOCK_STREAM);
			if (!socket) {
				if (err)
					*err = -1;
				return NULL;
			}
			if ((socket->Connect(remote) != 0) && !socket->IsBlocking()) {
				if (err)
					*err = socket->GetError();
				delete socket;
				return NULL;
			}
			if (err)
				*err = 0;
			return new SocketStream(socket);
	}

	void
		NewSocketPool::ReturnConnectedStream(StreamInterface* stream) {
			Thread::Current()->Dispose(stream);
	}

	//////////////////////////////////////////////////////////////////////
	// ReuseSocketPool
	//////////////////////////////////////////////////////////////////////

	ReuseSocketPool::ReuseSocketPool(SocketFactory* factory)
		: factory_(factory), stream_(NULL), checked_out_(false) {
	}

	ReuseSocketPool::~ReuseSocketPool() {
		ASSERT(!checked_out_);
		delete stream_;
	}

	StreamInterface*
		ReuseSocketPool::RequestConnectedStream(const SocketAddress& remote, int* err) {
			// Only one socket can be used from this "pool" at a time
			ASSERT(!checked_out_);
			if (!stream_) {
				LOG_F(LS_VERBOSE) << "Creating new socket";
				int family = remote.family();
				// TODO: Deal with this when we/I clean up DNS resolution.
				if (remote.IsUnresolvedIP()) {
					family = AF_INET;
				}
				AsyncSocket* socket =
					factory_->CreateAsyncSocket(family, SOCK_STREAM);
				if (!socket) {
					if (err)
						*err = -1;
					return NULL;
				}
				stream_ = new SocketStream(socket);
			}
			if ((stream_->GetState() == SS_OPEN) && (remote == remote_)) {
				LOG_F(LS_VERBOSE) << "Reusing connection to: " << remote_;
			} else {
				remote_ = remote;
				stream_->Close();
				if ((stream_->GetSocket()->Connect(remote_) != 0)
					&& !stream_->GetSocket()->IsBlocking()) {
						if (err)
							*err = stream_->GetSocket()->GetError();
						return NULL;
				} else {
					LOG_F(LS_VERBOSE) << "Opening connection to: " << remote_;
				}
			}
			stream_->SignalEvent.disconnect(this);
			checked_out_ = true;
			if (err)
				*err = 0;
			return stream_;
	}

	void
		ReuseSocketPool::ReturnConnectedStream(StreamInterface* stream) {
			ASSERT(stream == stream_);
			ASSERT(checked_out_);
			checked_out_ = false;
			// Until the socket is reused, monitor it to determine if it closes.
			stream_->SignalEvent.connect(this, &ReuseSocketPool::OnStreamEvent);
	}

	void
		ReuseSocketPool::OnStreamEvent(StreamInterface* stream, int events, int err) {
			ASSERT(stream == stream_);
			ASSERT(!checked_out_);

			// If the stream was written to and then immediately returned to us then
			// we may get a writable notification for it, which we should ignore.
			if (events == SE_WRITE) {
				LOG_F(LS_VERBOSE) << "Pooled Socket unexpectedly writable: ignoring";
				return;
			}

			// If the peer sent data, we can't process it, so drop the connection.
			// If the socket has closed, clean it up.
			// In either case, we'll reconnect it the next time it is used.
			ASSERT(0 != (events & (SE_READ|SE_CLOSE)));
			if (0 != (events & SE_CLOSE)) {
				LOG_F(LS_VERBOSE) << "Connection closed with error: " << err;
			} else {
				LOG_F(LS_VERBOSE) << "Pooled Socket unexpectedly readable: closing";
			}
			stream_->Close();
	}

	///////////////////////////////////////////////////////////////////////////////
	// LoggingPoolAdapter - Adapts a StreamPool to supply streams with attached
	// LoggingAdapters.
	///////////////////////////////////////////////////////////////////////////////

	LoggingPoolAdapter::LoggingPoolAdapter(
		StreamPool* pool, LoggingSeverity level, const std::string& label,
		bool binary_mode)
		: pool_(pool), level_(level), label_(label), binary_mode_(binary_mode) {
	}

	LoggingPoolAdapter::~LoggingPoolAdapter() {
		for (StreamList::iterator it = recycle_bin_.begin();
			it != recycle_bin_.end(); ++it) {
				delete *it;
		}
	}

	StreamInterface* LoggingPoolAdapter::RequestConnectedStream(
		const SocketAddress& remote, int* err) {
			if (StreamInterface* stream = pool_->RequestConnectedStream(remote, err)) {
				ASSERT(SS_CLOSED != stream->GetState());
				std::stringstream ss;
				ss << label_ << "(0x" << std::setfill('0') << std::hex << std::setw(8)
					<< stream << ")";
				LOG_V(level_) << ss.str()
					<< ((SS_OPEN == stream->GetState()) ? " Connected"
					: " Connecting")
					<< " to " << remote;
				if (recycle_bin_.empty()) {
					return new LoggingAdapter(stream, level_, ss.str(), binary_mode_);
				}
				LoggingAdapter* logging = recycle_bin_.front();
				recycle_bin_.pop_front();
				logging->set_label(ss.str());
				logging->Attach(stream);
				return logging;
			}
			return NULL;
	}

	void LoggingPoolAdapter::ReturnConnectedStream(StreamInterface* stream) {
		LoggingAdapter* logging = static_cast<LoggingAdapter*>(stream);
		pool_->ReturnConnectedStream(logging->Detach());
		recycle_bin_.push_back(logging);
	}

	///////////////////////////////////////////////////////////////////////////////

} // namespace base
